Abstract
To regenerate plants by ovary culture of pea (Pisum sativum L.), the effects of the developmental stage of explants and cultural conditions on seed formation and germination were investigated. 1. The more mature the explants were, the more frequently they formed seed and germinated in an ovary, ovule and embryo culture. Among these three culture methods, the ovary culture regenerated plants most efficiently. Therefore, it seems suitable for accelerating generation turn-over by in vitro culture of the pea. 2. When an excised ovary was cultured before anthesis, the ovule failed to grow, whereas after anthesis, the older the ovary was, the faster the ovules grew and germinated. 3. Ovules of 'Misasa', 'Oranda' and 'Kishu-usui' grew and germinated in an ovary culture. 4. In an ovary culture, the ovule germinated faster at 25°C than at 20°C. 5. The addition of NAA 0.5 mg·liter-1, NAA 1.0 mg·liter-1 or BA 1.0 mg·liter-1 to the medium promoted the growth of the ovule in an ovary culture but the addition of GA3 0.5 mg·liter-1 suppressed it. 6. By changing the stopper of the test tube to cotton instead of aluminum foil after germination of the 'Misasa' ovule in an ovary culture, shoots grew well ; 100% of the plants flowered and bore fruit in vitro.
